Running and training: understanding the different paces

As training is based on varying pace from one session to the next, it is essential to know what pace to run at during your various outings. Read on to gain a clear insight.

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Whether you are a newcomer or used to fastening on race numbers, at one time or another, you have been struck by this feeling: the different running or training speeds are a jungle in which it is best to possess a compass to avoid getting lost.

“Between VVO2max, threshold and specific paces, people sometimes find it hard to find their way around, especially if they are training alone. So, I prefer to talk about specific paces for particular distances, which always correspond to their record or target pace for a particular race”.
Olivier Gaillard, FFA running coach and designer of the training programme for the 2024 Marathon for All.
Coaches introduce a simple formula. To focus on the detail, they talk of ‘AS42’ for the target pace or objective on a marathon, ‘AS21’ for the same over a half marathon distance, and ‘AS10’ for a personal best over 10 km – most runners preparing for a marathon have already covered this distance. However, there are less well-known or less often used formulas: AS5 (for 5 km) and AS2, for 2 km run at top speed, which also corresponds with velocity at maximal oxygen uptake pace, the famous VVO2max.
Why is it necessary to determine and know all these paces? Because they will serve as a basis and reference for training sessions. Training and progressing means being able to vary your pace during training and switch between AS42, AS10 and AS2 in the same week. Let’s take a closer look at this.

Basic endurance: “It is the foundation of training,” explains Olivier Gaillard, “a jogging pace where the heart rate remains fairly low and the pace is controlled. You should be able to speak whilst jogging. This pace is used all the time in training, when warming up, when jogging... you are basically running at 60% or 70% of AS2 (see below). It should be noted that for runners aiming for a marathon time of 4 hours or more, the basic endurance pace is very close or equal to their target pace over this distance, namely AS42”.

AS42: the target pace (or objective) on a marathon: “The target marathon pace, or the pace already achieved for those who have already run one, means that you can incorporate training blocks at this speed into your long weekend outings,” adds Olivier Gaillard. “To determine this, you can start from your record pace over 10 km or a half marathon and subtract 1 or 1.5 km. Alternatively, double the time for the half marathon, and add between 15 and 20 minutes to the total to obtain your AS42. Runners who have never run a marathon before need to beware, however: you never know how they will react over long distances, or at the wall they tend to hit after the 30-kilometre mark. There are many parameters to consider. This AS42 pace must be an achievable goal: if you have completed a half marathon in 1 hour and 55 minutes, then aiming to finish a marathon in less than 4 hours is not realistic. You need to avoid asking too much of your body…”

AS10, AS21: personal best paces on a 10-km race and half marathon: “Knowing your personal best over 10 km will allow you to work at this speed in long split intervals, between three and ten minutes, such as 10 x 3 minutes or 7 x 4 minutes,” points out Olivier. “During these sessions, you should try to maintain the same pace, so that you can get used to being consistent over marathons too. For people who have never run a 10-km race or a half marathon, this pace can be estimated at 85% or 90% of AS2. Many runners use the term "threshold" to define this pace, but this concept takes many parameters into account and is sometimes vague. I like to place this session at AS10 the day before the long run, in a sort of “weekend training block”: this allows you to tackle the long run, which will never be the distance of a marathon, with a pre-fatigue that simulates a longer effort thanks to the sequence of sessions”.

AS2: the quickest pace at which you are capable of running over a 2-km effort:
“It should be pointed out here that there is no better way of learning a pace, especially AS2 or VVO2max, than going and joining a club and discussing with one of the coaches,” underlines Olivier. “Several tests, such as the Luc-Léger test or the Vameval test, can be used to determine it fairly accurately, but they are difficult to carry out alone. However, if there is no other option, AS2 corresponds to the maximum pace a runner is capable of keeping over 2 km, with the feeling that they cannot do any better. If you test yourself in this way, you need to spread out your effort and not start too quickly. A smart watch that can measure your heart rate can be very useful: the aim is to reach your maximum heart rate at the end of this test, for around one minute. In training for marathons, this reference pace is used particularly during the first few weeks of the plan, alternating with hill running sessions”.

The Marathon for All route: the right frequency for the right pace
Olivier Gaillard has one last piece of advice to give us, directly linked to the particularities of the Olympic route: “the Olympic Games marathon will not be flat but bumpy. When you run at AS42, your heart rate will not be the same on the flat as on a slope. So, you need to determine your AS42 on the flat and, for those who can, check your heart rate at this pace on the flat. Then, during a long training session on hilly terrain and even on race day, run not according to your pace, but according to the heart rate that corresponds to your AS42 on the flat. You will inevitably go slower, but you will still be putting in the effort needed to run a good marathon. It is not a question of marathon pace sessions, but marathon intensity sessions. In such a case, heart rate monitoring is a very useful tool”.

Article written in association with the French Federation of Athletics.